The present invention relates to new additives suitable for use in aminoplastic resins; it relates especially to new acrylic additives derived from urea.
Acrylic derivatives of urea are already known. The acrylic compounds used as starting substances are most often acrylamide and acrylonitrile. Thus, the polycondensation of urea, formaldehyde and acrylamide in a weakly alkaline medium with a view to preparing methylolated products, followed by the addition of styrene or methyl acrylate, has been proposed (in particular, Kostyukov et al. - USSR No. 277,550, 3rd June 1970). The preparation of acrylic derivatives of urea from methacrylamide, formaldehyde and urea has also been proposed (French Application No. 85/06,106). A new process for manufacturing acrylamidomethyleneurea has also been described (French Application No. 85/06,103), which process consists in reacting, in a first stage, acrylamide with formaldehyde in a basic medium with a view to obtaining monomethylolacrylamide, and then, in a second stage, in reacting the latter compound with urea in an acid medium.
In the above cross-referenced application, New Acrylic Derivative of Urea, a new product of formula: ##STR1## which is monomethylolacrylamidomethyleneurea, is described. It has now been found that new products based on monomethylolacrylamidomethyleneurea enable this acrylic derivative to be used in a form such that its separation from the reaction medium is not required.